Standard Tea Intake Is Causally Associated with a Reduced Risk of Wet Age-Related Macular Degeneration: A Mendelian Randomization Study

Researchers have posited that increased consumption of tea and coffee may be associated with more favourable treatment outcomes in patients with age-related macular degeneration (AMD). However, there is no clear evidence regarding the causal associations. To delve deeper into this potential connection, scientists employed a rigorous method known as Mendelian randomization (MR). This technique was utilized to explore the causal impact of tea and coffee consumption on the development or progression of AMD. With the aim of investigating the cause-effect relationship between 16 tea and coffee consuming subtypes and 3 AMD, we designed a two-sample MR-study using comprehensive data from genome-wide association studies (GWAS). The major approach adopted was inverse variance weighting (IVW). Furthermore, we implemented complementary methods like the weighted median (WM), weighted mode, and MR-Egger to strengthen our findings. Sensitivity analyses, including MR-Egger, MR-PRESSO, leave-one-out, and Cochran's Q tests, were employed to validate results, explore heterogeneity and pleiotropy, and pinpoint potential biases. 268 instrumental variables were selected for MR analysis. The results showed that standard tea intake may be a protective factor for wet AMD (OR=0.7076, 95%CI=(0.5776 - 0.8668), P=8×10-4, PFDR=0.0402). Sensitivity analysis suggests that the results are robust. Our findings provide genetic evidence that standard tea intake is a protective factor against wet AMD, providing new insights into early risk stratification and prevention strategies for the disease.